1) STOP TYPING IN ALL CAPS!!!! It is considered screaming.
2) What specific problems are you running into with these devices? There can be so many problems, it would be easier if you told us what you are experiencing.
Hello I have a crt board that keeps blowing fuses.the removable chips are MM2102AN-4 MM2102AN-4L . I was checking the connection in the sockets and after I pulled the chip out of my thumb,I accidently bent some pins on several chips.I broke one of the pins on a chip while trying to straghten it back out.I also inserted 2 of the chips in the wrong direction(distracted while digging the chip out of the thumb).I also "now" know how to orient and find #1 pin. Just to late for those 2 chips that I inserted in the sockets backwards. I did apply power after I thought that I had all of them in order. no crt screen My question is is it worth trying to trouble shoot these 8 chips or to just buy new ones? They are available online for about 4-5 dollars / pc. Thank you
Is this equipment from the late 70's or early 80's? And then you said you had eight of them. Without even looking, I would say this is a device with a microprocessor and these are the 1K memory chips. I would replace all of them. I'm shocked that you can still buy them. Wish I could sell all the 2102 chips I have for $4-5! Question you have to ask is will that solve all your problems or get you back to the first one.
I believe that the cnc is dated around 1980.I spoke with someone the other day,and they told me that these mm2102an-4 and 4l were the same animal and that they couldnt see anything different between them.Some one else said that they were resitors.??? I do not know what these chips are for or even if the call out 4-4l are the same. The reason that I suspected these chips,, I talked to a few electricians and they did look at the board and said that I should make sure that these chips were seated good in the sockets.After I removed a few of them and plugged them back in,I did get a new screen to show up on the crt. not 100% of the time so that is when I removed the board and broke a few pins trying for that better fix. I will buy new chips for the board. I do not know where this fix will go.Hopefully this will be a step in the right direction.I am willling to take the chance that these chips(3 pcs my fault) are bad and that this is a step towards fixing the board. Thank you.
Rondel,
Delphi electronics says these are 1k x 1k sram (memory) chips manufactured by National Semi a long time ago as stated above by OH. Without a schematic it can be difficult to TS a PCB. If the fuse takes a while to blow you might try touching carefully around the board components to see if one burns your finger or maybe use a Ir camera to locate where the power is going. Be careful since there can be high voltages if this board also has the power transistors for driveing the High Voltage Xformer on it. Another trick I'v used is to replace the Fuse with a large resistor and disconnect Parts (IC's and such) one at a time and note when normal circuit voltage returns since it will most likely be very low with the bad component installed.
Good Luck -elf
